The use of tobacco stems in the manufacture of smoking products has long been recognized as a desirable objective in view of the obvious economic benefits to be derived therefrom. The physical shape and properties of the stems, however, make it necessary to convert the stems into a form that will be compatible with the intended use. One approach that has been used is described in U.S. Pat. No. 3,556,112 wherein tobacco stems are first puffed and then sliced in a plane substantially parallel to the stem axes. This approach has inherent disadvantages including limited and non-uniform puffing of the intact stem as well as difficulty in aligning the puffed stems with respect to the cutting blade which must be of special design to prevent collapse of the puffed stems. Another approach is disclosed in U.S. Pat. No. 3,734,104 which involves rolling or crushing tobacco stems prior to cutting the flattened stems to filler size. The rolled, cut stems are then expanded in a hot, gaseous medium containing at least 30 percent by volume of steam. This latter approach also has attendant disadvantages in that the final dimensions of the expanded stem material tend to be quite variable because the rolling or crushing operation affects the degree of expansion that can be subsequently obtained. It is noted that this latter patent teaches cutting the crushed stems at 75 to 200 cuts per inch which produces particle sizes significantly smaller than conventional cut filler which is produced by cutting strip tobacco at approximately 30 cuts per inch. Thus, it is apparent that the success in producing cut, expanded stems of uniform filler size using this latter method depends on uniform expansion of cut stem material that is less than cut filler size. Inasmuch as the integrity of the cell structure within the stems is affected by the rolling or crushing operation, it is virtually impossible to obtain uniform filler dimensions by the use of such a process.